Roof Flashings

Roof Flashings

Colorspan Industries are the experts when it comes to roof flashings, our standard range of Box Gutters, Valley Gutters, Apron and Capping Flashings can be manufactured to your desired profile.

Box Gutters

A box gutter is a rain gutter on a roof usually rectangular in shape, that may be concealed behind a parapet, an eave or in a roof valley. Box gutters are designed to suit large water carrying capacity requirements, usually on commercial buildings.

In effect, a box gutter operates like an open drain generally placed between parallel surfaces, as in a valley between parallel roofs or at the junction of a roof and a parapet wall.
Designing for a box gutter requires adequate support for the gutter be provided, both at the sides and below, to provide for the anticipated weight of the water collected. As with all gutters, adequate fall must be provided as well as a rain-head or other large capacity drainage system.

Valley Gutters

A valley gutter is a shallow gutter shaped to suit the angle between two internal slopes of a roof. The valley gutter has a return along each edge to reduce the possibility of water overflowing into the roof space.

The valley gutter profile is similar that of a Box Gutter but with a V shape drain channel rather than square. Valley gutters or valley flashings which occur at the non-parallel intersection of roof surfaces, typically at right angled internal corners of pitched roofs.

Apron Flashings

Apron flashings prevent water from penetrating the space where a vertical surface intersects a roof. They also protect and support the underside of the roof cladding/ underlay to reduce damage by wind and solar radiation.

For maximum water proofing, it is advised to lap at two ribs along the metal sheet roofing, and wider apron flashings are advised when the base of the flashing faces into the prevailing wind. They also provide protection against wind-blown embers.

Cappings

Colorspan Industries manufactures a range of cappings to suit different applications. The three most common types of cappings are;

1. Ridge
2. Parapet
3. Barge

Ridge Cappings

A metal covering over the roof ridge to provide a continuous cover and effective weather seal between two slopes. The size of the edge break should conform with the rib height of the steel roofing to which the ridge is attached. Good roofing practice is to notch this edge break to neatly fit around each rib of the roof sheet.

Parapet Cappings

A covering used to waterproof and cap the ends of vertical sheets or masonry walls. A stiffening edge or break is often applied to the legs of the parapet cap for a more appealing appearance and to minimise oil canning of the metal. Ensure that these recommendations are taken into account when measuring the flashing. It is also important to ensure that water does not pool on top of the cap to prevent water seeping into the building.

Barge Capping

A folded sheet used to waterproof the junction between a fascia or barge board and roof sheeting. The size of the edge break should conform with the rib height of the metal roofing to which the ridge is attached.

Material Data

Colorspan Industries are able to provide profiles in a wide selection of material types and ﬁnishes to meet both aesthetic and performance properties. This ensures your project maintains design consistency without compromising on durability or functionality.

Colorspan Industries use Australian made Blue Scope Steel products including Zincalume®, Galvabond®, Colorbond®. Choose from the full Colorbond® range including Metallic, or request a custom material or ﬁnish to achieve your desired results.

Important:

1. You can run water along GALVABOND® onto ZINCALUME® but if you cannot run water from ZINCALUME® to GALVABOND® as it will eventually corrode
2. ZINCALUME® is incompatible with lead flashing and copper piping